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Line A: a priority

The new double deckers MI09 trains can carry 2,600 passengers every three minutes, 50% more than the old rolling stock. They came into service on 5 December 2011 on the RER Regional Express line A.



RER A summer construction work: Visit our dedicated section at

30% regularity improvement on Europe’s most used urban line

By 2017, after approval by the Board of Directors, some 130 MI09s will be deployed, raising capacity by 30% on RER line A in Île-de-France, which carries more than a million passengers a day on weekdays. These new trains illustrate our commitment and proactive investment strategy. Our engineering department compressed the acquisition, validation and commissioning leadtimes for the new rolling stock to the absolute minimum without jeopardising safety. The first ten MI09s came into service at end-December, just 30 months after the contract was signed.

Line A, with its 20% growth in passenger traffic over 10 years, has been a victim of its own success – the slightest incident can have an impact on service regularity. The time between trains during peak hours has been reduced to two minutes on the central section thanks to RATP’s automatic train control system. The MI09s are equipped with air-conditioning, onboard security cameras (62 per train), an audio visual public address system for announcing station arrivals and traffic disruptions, and 34 seats reserved for disabled people.

RATP is financing 66% of a first tranche of 60 trains (€917 million in total), and STIF the remainder. RATP will operate the line at least until 2039.




  • Opening hours: 5:00 a.m. to 1:20 a.m.
  • 46 stations, 35 managed by RATP and 11 by SNCF
  • 76 km of track (including 26 km underground) out of a total of 109 km including the SNCF section
  • 207 trains in service
  • Stations in 7 of Ile-de-France’s 8 departments
  • 11 arrondissements of Paris and 75 neighbouring towns served
  • 2 eastern branches and 3 western branches
  • Serves several important centres of activity: La Défense, the central business district, Cergy and Marne-la-Vallée
  • Serves 3.5 million inhabitants (31% of the population of Ile-de-France) and 2 million jobs (41% of regional employment)
  • A commercial speed of 49 kph
  • Trains every two minutes during rush hour on the central section
  • Connections with all other RER lines (except line C), and 10 out of 14 lines of the metro
  • RATP sections: Boissy-Saint-Léger/Saint-Germain-en-Laye and Marne-la-Vallée/Nanterre Préfecture